John dierdorf



(No Model.)

J. DIERDORF.

PIANO TUNING PIN HOLDER.

No. 602,680] Patented Apr. 19,1898.

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WITNESSES UNITED STATES PATENT OFFICE.

JOHN DIERDORF, OF INDIANAPOLIS, INDIANA.

PlANO-TUNlNG-PIN HOLDER.

SPECIFICATION forming part of Letters Patent No. 602,680, dated April19, 1898.

Application filed October 4:, 1897- Serial No. 654,024. (No model.)

To ctZZ whom it may concern.-

Be it known that I, JOHN DIERDORF, a citizen of the United States,residing at Indianapolis, in the county of Marion and State of Indiana,have invented certain new and useful Improvements in Piano-Tuning-PinHolders, of which the following is a specification.

The object of my invention is to produce a device whereby the strings ofpianos may be efilciently held so as to be prevented for a comparativelylong time from getting out of tune. A further object is to provide asimple and inexpensive means of renewing the bearing parts when theybecome worn. These objects are accomplished by the construction ofpin-bearings hereinafter more particularly described and claimed.

Referring to the accompanying drawings, which are made a part hereof,and on which similar letters of reference indicate similar parts, Figure1 is a plan view of a piano stringplate and sounding-board,showing thestrings secured in accordance with my present invention; Fig. 2, afragmentary plan View, substantially full size, illustrating theconstruction more plainly, one of the tuning-pins being shown in fulland the other in section; Fig. 3, a detail sectional view on the dottedline 3 3 in Fig. 2; and Fig. 4, a detail View similar to a portion ofFig. 3, but showing my improved pin-holder when applied directly to awooden pin-block without a metal plate.

In said drawings the portions marked A represent the pin-block of thepiano; B, the iron frame which is usually placed over the sounding-board; G, the usual tuning-pins; D, the piano-strings; E, myimproved pin-holder, and F the sounding-board. All these parts are ormay be of any usual or desired construction, except the'pin-holders E.In the principal drawings that construction is shown wherein there is noiron frame. The construction and operation of my improved pin-holdersare, however, substantially identical in both cases. v

The tuning-pins O, as is usual, enter the pin-block A. They are,however, supported by my improved pin-holders E. Said pinholders areround disks with, preferably, V- shaped cuts or notches therein toreceive the pins, and the pins bear against the sides of said cuts ornotches, as shown. As will be readily understood, when these pin-holdersbecome worn and smooth they can be taken out and their bearing -surfacesroughened slightly, if desired, or they can be removed altogether andnew ones inserted in their place, the expense of either work beingtrifling.

There are several disadvantages incident to the ordinary means andmethods of securing the tuning-pins in the pin-blocks of pianos. Whenthe pins are mounted in the wood alone and not supported by any metalbearing, the wood wears and yields in a comparatively brief time. Thebearings thus become loose, so that the pins will not hold, and theinstrument soon reaches such a condition that it rapidly gets out oftune. Where the pins bear against ordinary openings in the iron plates asimilar result occurs in a somewhat greater time. In either case inorder to-correet the evil results a comparatively large expense must beincurred, as the pins require to be hushed or the pin-block or theplate, or both, renewed, any of which methods are quite expensive. Inthe old construction,also, the strings are attached to the pins at apoint comparatively distant from where the pins enter the pin-blocks, sothat the strain is much augmented on the hearing by reason of theincreased leverage. There the holes in the pin-block fit the pin tightlyfor the full length,

great difficulty is generally experienced in extracting the remainingportions of pins after, as is frequently the case, the upper ends of thepins are broken off.

By the use of my invention these disadvantages are overcome. The pinsimpinge tightly between the opposing converging sides of the cuts ornotches in the pin-holders, and are thereby held to position veryaccurately and with great strength. The upper bearing-point is also veryclose to the point where the strings are attached. The holes in thepin-blocks being tapered at the upper ends, the pins can be manipulatedmore easily and accurately, the friction being at the lower or innerends of the pins and at a point near where the strings are attachedonly. With these tapered holes, as above stated, broken pins can also beextracted more easily.

Having thus fully described my said invention, what I claim as new, anddesire to secure by Letters Patent, is-- block having tapered pin-holes,pin-holders E secured at the upper side of the pin-block and havingsuitable notches in their sides to receive and hold the pins, saidtuning-pins, and the piano-strings connected thereto, all substantiallyas shown and described.

3. The combination, in a piano, of the strings, the tuning-pins, apin-block having, tapered pin-holes, and pin-holders consisting of diskshaving suitable notches in the sides thereof to receive the pins andsecured at the upper side of the pin-block, whereby said pins aresupported at and near their points and at a point where the strings areattached thereto, substantially as and for the purposes set forth.

In Witness whereof I have hereunto set my hand and seal, atIndianapolis, Indiana, this 28th day of September, A. D. 1897.

JOHN DIERDORF. [L. s.]

Witnesses:

CHESTER BRADFORD, JAMES A. WALsH.

